Skylight

摘要

An improved skylight having high structural strength and improved insulation capabilities. A sheet of polycarbonate plastic is formed into an outer dome having an extended flange around the perimeter of the dome. The extended flange has first and second steps formed therein adjacent to the perimeter of the dome. A second dome having its narrow flange around its perimeter forms a middle dome having its narrow flange fitting into the first of the steps in the flange of the outer dome and having its dome spaced a short distance from the outer dome to provide a narrow dead air space having good insulation properties. A third dome having a narrow flange around its perimeter forms an inner dome in which its flange will overlap the flange of the middle dome and fit into the second step in the outer dome flange and having the inner dome spaced a short distance from the middle dome providing a second insulating dead air space to minimize heat flow through the three domes. The middle dome flange is bonded to the first step portion of the outer dome flange and the inner dome flange is bonded to the second step portion of the outer dome flange and to the inner surface of the middle dome flange. During molding of the outer dome a sharp rise or push essentially perpendicular to the outer dome flange is formed between the first step and the dome of the outer dome to prevent interference between the inner surface of the outer dome and the outer surface of the middle dome.